Structural Control of Cell Permeability with Highly Emissive Europium(III) Complexes Permits Different Microscopy Applications. Issue 2 (16th December 2015)

• Record Type: Journal Article
• Authors: Starck, Matthieu; Pal, Robert; Parker, David
• Is Part Of: Chemistry. Volume 22:Issue 2(2016)
• Page Start: 570
• Page End: 580
• Publication Date: 2015-12-16
• Subjects: cell imaging -- europium -- luminescence FRET -- microscopy; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201504103
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: Four anionic europium complexes are described based on triazacyclononane tris‐carboxylate or phosphinate ligands. In each case, the three sensitising chromophores comprise a substituted aryl–alkynyl pyridine group, with complex brightness in water falling in the range 4 to 23 mM −1 cm −1 . para ‐Substitution of the aryl ring with carboxymethyl groups gives complexes that are taken into cells, stain the lysosomes selectively and unexpectedly permit lifetime measurements of lysosomal pH. In contrast, the introduction of sulfonate groups inhibits cell uptake enabling the Eu complex to be used as an extracellular donor for FRET applications at the membrane surface. Using time‐gated FRET microscopy, the cell membrane structure was highlighted, in which Cell Mask Deep Red was used as a membrane‐ localized FRET acceptor. Abstract : A set of four very bright europium complexes has been synthesized, in which cell uptake is controlled by peripheral substitution on the sensitising chromophores (see figure). The internalised pair of complexes stain the lysosomes and allow monitoring of lysosomal acidification; the non‐internalised pair allow membrane imaging by TR‐FRET microscopy.